obvious back in the day , very little went too waste.
think walnut would give more board feet per tree
least straighter longer cuts... vs maples.
On what do you base the "longer cuts" on?
Back in the day cutting planks was too much work to waste on poor wood. A great deal of timber that would be worth major dollars today was simply burnt since there were no market for it.
My father back before WW-II talks of clearing land in Ark. And working with a cousin to saw large straight oak logs in the pieces small enough to move then their being rolled together and burnt. Logs so large the a 6 ft cross cut was barely long enough to cut them.
So forget the waste thing its irrelevant in the context of the time .
Baseball bats. I suspect that this is the highest stress use of wood.
So far as bats breaking, I admit to being ignorant of MLB having bat problems since I don't recall watching an entire game in my life, I did a little research and found that there is a problem but a considerable part of this is in the selection of the wood itself. Grain flow and hardness. But broken bats has little to do with gunstock woods.
They use maple because it puts more energy on the ball.
I like maple for gunstocks because for my purpose its the best choice for looks, durability, the ability to hold carving and historical correctness. IF its good hard maple.
While there are original rifles and fowlers stocked in a variety of woods curly maple is found everywhere.
In the 19th century, at least after the Civil War more and more guns were stocked in Walnut. Why I could not say unless it was because the breechloaders were invariably stocked in Walnut and it was what people were used to.
It suitability for gunstocks American black walnut rates at least 3rd and perhaps lower.
European Walnut and Hard Maple are both superior and Cherry might be as well but I have no experience with it.
I think walnut was used because it was cheap and plentiful compared to other woods and looks great with nothing more than a coat of oil in most cases.
Dan